Hi everyone.

I’ve been reading quite a few (long) threads about gyrators, and most of them are old enough to (maybe) justify creating this new one. Sorry in advance, if this was not the most appropiate decision. Also, all simulations I’ve seen show the loaded stage gain vs frequency, not the impedance.

Attached, two simple gyrator circuits for anode loading, based on pmos devices, like users like Wavebourn and mogliaa have suggested.

While it is possible to get decent AC impedances:
- left circuit (green trace) acts as an inductor only up to about 750 Hz, then impedance is capacitive. Is this the correct behaviour?
- right circuit (magenta trace) acts as inductor below 10 Hz, then seems like a CCS (not impressive impedance, though, below 400kohm) but no inductive reactance is present (V-I phase is zero). Again, is this correct?

As far as impedance is concerned, I’m able to achive higher impedance using CCS, and much flatter with frequency.

I’m suspecting errors or misunderstandings on my side, so I apprecite very much any correction or advice.

hi,

i am doing a bachelor degree in electronics, and thought it would be very cool do build myself a dac to go along with my diy hifi speakers. maybe i can use this project as my thesis.

is it doable? i am not just looking to put a board into a box and call it the day as some of the diy kits seem to be.

i am not really sure where to start though.. i have no specific budget, so let's say under a 1000 bucks.

ESS Sabre ES9038PRO seems to be a 'go to' chip, correct? is this really the best? it's about 90 euros

Several postings mention that for a triode in A2 mode, i.e. with cathode voltage below the grid voltage, the grid starts to become a second cathode leading to substantial current flowing from Anode to Grid, causing less current to arriving on the Cathode.
In that case, Ianode would be Igrid+Icathode.

However In my simulation of a GM-70 I see the opposite, where the Grid starts to become an Anode sourcing current to the cathode.
So Ianode + Igrid = Icathode.

Is my simulation model correct or not ?

Hans

Quick intro:
I'm a 41 year old tech product manager in the world of web and mobile apps. I have a few RPi projects in the works as well as an Unraid NAS set up on a ZimaCube... this is all to say, I have some toys but really I know very little aside from what I learn quickly through internet/youtube/GPT conversations. I have some tech issues that I'd love to get answered and learn more about this world in general to make upgrades where possible.

Hello.

I have made a pair of pencils with the alpair 10p, and i
love them.
Now i have bought 2 pairs of alpair 10.3m, and i wonder
if there is any good encloseures with dual elements in
them? or a good encloseure that goes lower than the pencil.
Room is about 27m2.
I have looked around on the Internet, but have not found any with dual alpair 10.
Sorry for my english 😊

Best regards.

Paul

I have 3 fried plate amplifiers from powered subwoofers. I am quite certain of which components cooked on at least 2 of them and at least think I know what cooked the 3rd. It looks to be capacitors on one of them, resistors on another and possibly capacitors again on the 3rd. 2 of them are the exact same model, JBL Venue series Sub-12s.

One of them is quite obviously a capacitor by the visible signs of a catastrophic explosion which disintegrated the cap and left a significant burn hole on the board. Enough to melt a hole in it and the pathway. I've determined that this board is not repairable. Or at least beyond my abilities at present nor worth it to me otherwise.

The board from the other one is the one with obvious resistor failure. The 2 larger ones were also catastrophically destroyed. The leads and a skin like shell were all that was left of them. There are burn marks there on the board as well although not nearly as severe as the first one.

The 3rd one is from a Definitive Technology 10" sub that has signs of excessive heat in a couple of places on the board but no obviously exploded parts. The worst of them are in the area where a few things could be the issue but I think it's one of the ICs or the caps that are close to it in the worst of the overheated areas.

All 3 drivers are still fine, tested with a known working amplifier. I'm only interested in using one of the 12" JBL drivers as a non amplified sub. I have an amp and PSU that will drive it but it's a full range amp so I need a low frequency signal only for the sub which requires a high frequency filter. I'm not sure if that's actually what a crossover is called technically but in any case I'm quite certain that I have the components for what I need between the other parts on the boards.

I'm capable of soldering and salvaging the parts but I'm not clear on exactly which ones or how to build the path for them to work for what I need. Does anyone have a detailed explanation or able to at least point me in the right direction. I realize that I'll have to build it on a generic PCB and make all the pathways myself and I'm quite certain that I can if I have a road map of how the parts have to be connected and which ones I need.

So in short what I need is a list of parts and how to build a board in order to filter out the frequencies higher than say 150hz and lower than 30 or so or recommendations otherwise.

Hi all,
Looking to get the current MAOP 7 for a desktop/tube setup. The speakers will be positioned close to the front wall (which is also a window). Space (depth) is very limited also, 19cm tops, hanging from the window-sill. Looking for something easy to build but sounding to the potantial of MAOP 🙂

I have no experience (or tools) in woodworking, so might be just outsourcing the build to someone who has. No experience in speaker building either, so don't judge too harshly.

Have had a look at the MA box plans. https://www.markaudio.com/online_shop/7-cm/maop-7/

• The vented one has a rear port and a bit too deep, but I suppose the BR can be moved to the front and depth reduced and volume compensated in width/height without affecting the tuning?
• The closed one looks interesting, but the bass response seems very limited. Tried simulating in WinISD, see below. How would that sound in real life? No bass whatsoever, or OK-ish? Otherwise, why would someone want such a speaker? Maybe that would work fine in my placement?
• The slot vent one - any advantages over the usual BR?

Also, they all say the below, can someone please explain the meaning?



Maybe there are other plans you can suggest also?

First listening test with brand new drivers in a 14 liter Golden Ratio box. B15xH39xD24 cm inside.
A little brighter than with 10Maop but it is marginal. Nothing that stands out, but it feels like a properly balanced sound. Between 10Maop and Alpair 11MS in terms of the tweeter level.
Maybe I'll wait a week or so before I've recorded these.
It may happen that they soften over time.
The midrange feels good.. The bass is there.. I'll try different lengths of the bass tube.
So I'll report back when I've listened a little more. Started with dia 32 mm x L16mm.

I made an F5M from the local kit. Gosh, it sounds pretty good!

But I've got some other amps, and they also sound pretty good. Hmmm, how good is good? Which one is goodest? Not to get all tangled up in hierarchy, but it seemed like some good A/B listening comparison was in order. So I've made a mess of the living room, and set it up.

First, I picked up a switching box. Getting up and fooling with plugs and switching things around every time? I wasn't into it. I want to click-click rapidly between amps. It seems like this might be a good candidate for a DIY project, but the idea didn't spark joy in my heart. I elected instead to buy this unit: https://www.amazon.com/dp/B0CY7T282N?ref=ppx_yo2ov_dt_b_fed_asin_title LYNEPAUAIO 3 Input 3 Output Power Amplifier and Speaker Switcher. I looked for a while at speaker only switchers, thinking I could run it backward, but none of them seem to have exclusive switching, allowing multiple speakers to be powered by the amp at the same time. I didn't fancy cross-connecting my amps, so I got the one I got. It'll take 3 amps, and 3 pairs of speakers. Amp selection is exclusive (selecting one deselects all others), but speaker selection is not (multiple pairs of speakers may be connected). It comes with some impedance protection - 2 ohms in series with the output. First I listened with that in place, then I removed it. It also says "Signal input provides vacuum tube power amplifier signal no-load conservation function" but IDK exactly what they did and can't speak to its functionality. This is a passive device.

Ok, I can switch 3 amps! Which 3? The F5M is the guest of honor. Also appearing is inexpensive TPA3250 board (https://www.amazon.com/gp/product/B0B258YS3B/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1), and AudioSector LM3875 chip amp.

That's the amps, what speakers? My main getup is active, and I've got only the 2 channels of F5M to have this little soiree, so the speakers will be reserve duty units. I completed these a bit ago: https://www.diyaudio.com/community/threads/trying-to-get-the-best-out-of-cheapo-piezos.409639/ Yes, the ugly truth comes out. Piezos. I had a chance to A/B these speakers (oh my, I sense a theme) with some Focal CMS65 active monitors, and I thought they were in the same ballpark. Mine have better horizontal dispersion, but worse vertical, and mine have a slightly breathier tonal balance but only by a bit. Measurements of mine in the above thread (see post #22, but details all over), but I didn't measure the Focals, they aren't mine. I've since put in a notch to address the 11 or 12 kHz peak, but haven't updated the thread yet. Anyway, I went to some effort to get good performance from the piezos and I think they do pretty well for it. Tough to believe, I know.

Alright that's sorted, piezo grublings aside. How will we drive them? What are the chances that these amps have the same gain? Having already investigated, I'll tell you the chances are nil. To deal with this, I drove the amplifiers from a computer with an 8 channel sound interface. I can set separate gains on each output, and used a DVM and 1kHz tone to equalize output. After that output levels to my ear seemed identical.

So many words already, how did it sound!? Hush, if it were simple it wouldn't be interesting, now would it?

Listening session #1 - output impedance protection (2 ohm) in place
This is quite close. Bass and dynamics were a match between all 3 amps. Tonality seemed very similar also, but after spending some time listening the F5M seemed a bit brighter. But the image is where these amps started to differentiate. The F5M seemed to have a bit more HF, but the image was spread back from the amp in space. This seemed like an odd pair of charecteristics to me. Also there seemed to be more space around musical elements. The TPA3250 brought the music up to the plane of the speakers and flattened out the image. The LM3875 was like the TPA3250, but more flattened and presented as located at the speakers. My wife and I both liked them in that order, 1st place: 5FM, 2nd TPA3250, 3rd LM3875. My wife said she sometimes thought the 5FM didn't do as well presenting big-sound, noise-type moments in music, but in the end still it was her favorite. That being said, they were more similar than different, and all generally competent.

Listening session #2 - removed switchers 2 ohm protection
I'm only using this one set of speakers, and maybe that extra resistance has some effect. Let's pull it and have another listen! This time - dang! They all sound very similar! I couldn't detect the same preferences I had earlier. The primary difference I was able to notice was that the F5M sounded a bit wider. What's going on? I did up the bias on the F5M in my hot garage, and on a hot day. Perhaps it is appropriate to re-evaluate the bias? The F5M info I have says "Voltage / 0.47 = bias amps For 1.1 amps the voltage is 0.52V and for 1.4 amps it is .80V". I had gone for ~0.55V initially, but now I was measuring 0.4something. Maybe that's my issue. I had noticed that it wasn't feeling as hot to the touch as when I first did it up, maybe some value had shifted? Let's heat this thing up. I re-biased to V across R6 ~= 0.75 v.

Listening session #3 - re-biased the F5M
Hey, that's pretty hot. Also, it smells like hot electronics. I feel like I read some comment that someone had up-specc'd R6 / R7 from 2W to 5W due to hot-resistor smell. But hey, the F5M is back in first place again. The spacious sound has returned. At this point the TMA3250 and the LM3875 were pretty similar. The differences all-around are not as large as they were in the first session. The F5M heat sinks get to 125 F in spots as measured by an infrared thermometer. I may get the 5W resistors, and / or reduce bias some. I do wanna keep that sound. I have a speaker project in mind more tailored to the F5M, passive XO, higher efficiency, higher impedance.

Goofball ideas

• So, maybe that 2R series resistance was having an effect, huh? Speaker resistance is 4R for the woofer and big/capacitor for the piezo. I don't really know exactly how the speaker load will impact each of these amplifiers.
• I wonder if the F5M is getting a little stereo widening across the power supply, based on sesh2 impression and sesh1 "sense of space"? I wonder what F5M monoblocks sound like compared to single PS versions.
• The sense of depth from the F5M - this rather matches with what Mr Pass has said about his preferred neg phase 2nd harmonic. Maybe further research along the lines of H2 generator + TPA3250 is in order. Or, there's a TPA3255 board on Amazon for not much $$$...

So Burning Amp 2024 is coming up in a few weeks here. I'm thinking I will bring this setup along and those in attendance can have a listen.

Whadya think?

Hey guys, I have the version for Coleman reg. from 2011, and I am planning to use it for a 6B4G build.

It’s been sitting on a shelf since 2011 and it’s time to put it to good use. I have a one ohm sense resistor soldered in, but I can’t seem to find the data that led me to think that was the right value. I also have a pair of 12v 50va. Trafos…


The filament is 6.3 V at 1 Amp. And going through all the documentation I have, it seems like for each different tube The regulator is set up a bit differently, different resistor values, etc.


How can I determine what would be the correct sense-resistor, and supply voltage?

Thanks in advance

I made the circuit with carbon film resistors and added tone control as in the picture, the tone control was working.

I made the same circuit with metal film resistors to minimize noise, and since the electret capsule (AKG ck31) I used works with 3mah, I changed the supply resistor from 4.7k to 3.2k. and strangely the tone control stopped working.

It worked for me a little in the first version, but it doesn't work anymore.

When I speak close to the microphone while recording, the sound comes out as it should. But when I want to increase the gain and get distant sounds. To provide a full and linear sound in distant recordings due to the treble of the recorded sound. I need to add (100hz) bass boost (with knob) or tone control.

Can you help me on how to implement this correctly?
Is there any adjustment I need to make regarding impedance compatibility?

Best regard..

New AD1862N.
65usdpair + shipping 10usd.
Revolut or PayPal (+PayPal fee)

I have acquired a pair of Eminence ME15-2008 drivers. I am told the TSPs are: Qts 0.59, Vas 224 l,Qes 0.67 fs 46Hz. I'm trying to decide whether to dispose of them or find bigger cabinets.

Hello all,

I need some help identifying the problem with the ML No23 amplifier.
Left channel still works which is big help, but the right channel is broken. When the right channel broke I remember measuring 3v DC in the speaker terminals. In the attached schematic you can see the point after predriver where there should be + and -1.5v but for some reason both sides hit to the negative rail voltage around -80v. When I remove both unregulated VCCs I have 0v in the positive side and -3v in the negative side. If I remove the unreg VCCs from the working channel it keeps the + and -1.5v. I have already changed all the biggest caps from the board and the transistors Q25,26,23,27 because I suspected those. Transistors Q32-37 and Q44-49 are not connected. I have checked all the supply voltages and they are right. Any help is appreciated!

Br,
Handel

1 pair Lundahl 2745/8ma line out transformers. Briefly used in a project that I have no time to follow up on.

$190 net to me.

Up for sale Pearl 3 phono preamp. What you see is what you get. Preamp boards were installed in the cheaper version of Modushop enclosure than the one offered exclusively for Pearl 3. Also initially, I planned to use a different power supply but the one that comes with the kit turned out to be absolutely sufficient. Although, I haven't made an effort to put in the enclosure yet. Another, new enclosure for PSU is included in sale. Everything works as it should. SOLD ! FF Paypaled and shipped to lower US.

As it says above, many, not all tracks will start about a second in, I’ve been told it’s when an external Dac is used.
Bluesound Node 2i into Audiolab Mdac+ using Qobuz
Any suggestions please?

I'm quite experienced in electronics but this is my first audio amp of this type with quasi MOSFET output.
I am repairing a US Acoustics - USX-4085 amplifier I bought not working.
Says "USX4085 REV C silk" on the board. (It does not have the blue light bar)
The unit powered up with red protect LED lit.
I found two output IRF540A MOSFETs (Q213 and Q214) on channel 2 shorted.
I tested the remaining components in channel 2 comparing to good channels and all measured OK.
I removed the two output MOSFETs, clamped it back in the heat sink, and now the amp powers up with green LED and no red protect LED lit.
Main amp rails measure +25.5V and -25.4V and preamp rails measure +15.5V and -15.4V.

Thermal camera shows these components much warmer than the rest:
Q105, Q205, Q305, Q405 (Looks like maybe lower MOSFET driver?)
OPT1 (Looks like it gates the bias, perhaps muting?)
R29, R30 (Pre amp power supply)
R31 (Power supply primary snubber)

Questions:
1) I can't seem to be able to find the IRF540A as it's been discontinued an so far everyone shows no stock. IRF540PBF looks close but not sure. IRF540Z doesn't look like a good match. I'm unsure what the critical parameters are for a MOSFET in this application. Any other alternates which would work?

2) How do I set bias after replacing the MOSFETs and to check the good channels?

3) Anyone have a schematic for this amp?

4) Any other tests I should perform? ( New to car amps but have scopes, 6 digit dmm, HV diff probes, arb signal generator, etc. in my lab)

Thank you in advance for any help,
Rich

Greetings all.
Does anyone know or have access to; the specified values of the Secondary voltages of the original Dynaco 416 power transformer.
I will need to get 2 units made for 240v supply down here in Tasmania. I'm building two from scratch.
I've had no luck finding specifications (anywhere) and guessing the values may end up being expensive.
A point in the right direction would be very helpful.
Thanks in advance.

In perfect working order
Ideal for Set or Valve amps


£200
Collection from MK5 Buckinghamshire

These do have their grills which have been poorly made .

Hi,

fos sale a pair AXI2050 in original boxes in mint + condition.
Serial Numbers very close: #402265; #4022397

Asking: 750€ each
Location Germany ZIP:25569

BR Barossi

I’m an old school heavy metal bass player and like to talk equipment and sound in general.

Does anyone know a box modelling system which can output (most likely as well as graphs) the results ie/ eg the dB at Hz, - in numbers? In increments of say 5 or 10 dB

Goal: to save a lot of when comparing a “number of” options what I’m hoping some knows of
To compare the outputs of a number of different drivers much easier and quicker if the predicted dB figures (almost certainly as well as in graphs) are available in a simple, table of two rows. eg

16 Hz 20 Hz 30 Hz etc
x dB y dB …

< fyi I’ve always used Unibox, it’s excellent. even calculates impulse response 🙂 >

For 1, 2 up to a dozen drivers/ alternative alignment combinations graphs are fine. But it multiplies

To reduce room modes most likely I’d do two subs.
It’s a sizable investment, money, time and room space. So I’d like to model - don’t know yet, certainly more than 10, likely a lot more

As you’d imagine: size, number, manufacturers, and models
Deciding between one or two 12 inches/ one or two 15 inches/ an 18. five possible options - from a manufacturer who only offers one driver of each size.

Several of the better manufacturers have a much wider range. Yes you can get a fair idea from the specs which models are likely to be right for the application. But there would still be a few you might want to check. Off the top of my head there’s at least half a dozen manufacturers who make mostly excellent subs.

If you have data in a table form - for each driver/ alignment just copy & paste the two rows into a spreadsheet. comparing multiple options would be far easier than trying to compare different graphs.

Depending on the scale and size of the graphs, looking at a curve, you can probably estimate the numbers within a few dB. Do that on even five or 10 separate graphs, vs being able to put the actual numbers without estimating, all in one place. …

I'm not allowed to post on swap/meet for some reason (lack of privileges?) so I'm mentioning this here.

I'm having a mancave clear out and came across this amp that I made years ago that's basically the old Maplin design but using Alfet laterals as an output stage. Does anybody want this stuff including a spare 08NP16V5. Am looking to swap for a case of beer or two? 🙂

Upgrading some Sony 4650 & 5650 V-fet amplifiers, there are tantalum and 'solid aluminium' caps present.
How about to replace them... or not. Needed?
Polar caps replacing is obvious, but what to do with these? And there are several mylars too!
Any opinion is appreciated.

I have a Velodyne Microvee sub that, a couple of years ago, started humming for a couple of minutes after being powered on every time it was switched on (AC power applied and main power switch moved from off to on).

The solution was quite simple, rarely switch it off 😂.

Lately though it has got worse with the period that it hums for after switch on getting longer until, today, it wouldn’t stop humming at all.

The hum is classic mains (or harmonic of mains).

Opening it up, there is no evidence of physically damaged components (Main PSU caps are not puffed up for example).

Anyone have any suggestions? I’m especially curious as to whether the fact that it previously only hummed for a while after power on might give any clues? To me, it suggests PSU issues but I don’t know where to start.

I’ve seen a few threads on this sub developing a hum problem so it seems like a vulnerability of the design. I’ve not been able to find a commonly reported root cause though.

Hello,

I hope someone can tell me where i can find IEC but without inlet, like in the image.

Thanks a lot!

hello friends
I took this "attenuator" from an old piece of equipment from my company, I don't know exactly what it is, but I thought it could be done a little DIY and turned into an attenuator for my next project (radiotron 6c6 2a3 amp - jelabs).
If you could guide me on what it is and if something can be done, or is it just garbage.
Your great wisdom would be very helpful to me.
I'm still learning.
Thank you all

Hi, i’m Thomas
Thank you for letting me join your community!
I’m on steep learning curve in building speakers and hopefully one day getting the guts to build a tube amp in the future 😄
Have a great day!

Thomas

L_SMPS600 is a switching unstabilised power supply with bipolar output voltage.

• low switching noise;
• high output power;
• bidirectional synchronous rectifier suppressing pumping effect;
• increased capacitance of high-voltage capacitors;
• advanced control options;

The L_SMPS600 is a high efficiency, safety class 2 switching power supply specifically designed for use with UcD/NCore/Purifi amplifier modules. Key features include high efficiency over the entire load range, small form factor, low mass and very low radiated and induced EMI. The L_SMPS600 features overcurrent protection with a high turn-on threshold, combined with large primary electrolytic buffer capacitors for high performance and guarantees high dynamic power at the output of the connected amplifier.
Over the entire power range, the output transistors operate in switching mode at zero voltage and near zero current. The current through the transformer is close to sinusoidal, with a minimum of high-frequency harmonics, thus reducing radiated noise and increasing efficiency. The no stabilisation and very low characteristic impedance of the converter improves the dynamic performance .
The L_SMPS600 is equipped with an auxiliary +/-15V bipolar source and load control circuitry that interfaces directly with our S_AUDIO range of amplifiers as well as being compatible with UcD/NCore/Purifi modules. The STBY signal is generated for the load under conditions of mains voltage presence, no overcurrent, no overheating and after the end of soft start. In addition, it is possible to quickly switch off the power supply unit with an additional signal in case of external alarms. Optionally, the unit can be equipped with an auto switch-off circuit on presence of an audio signal with a timer, as well as an additional independent source of standby voltage 5V 100mA.

Physical characteristics:
Length, without connector/with connector connected, mm: 140/148
Width, mm: 110
Height from board level/on 8mm posts, max, mm: 43/51
Weight, with connectors, g: 340

Maximum allowable parameters:
Supply mains voltage, V: 230+/-15%
Supply mains frequency, Hz: 47-63Hz
Maximum long-term output power RMS, W: 350 W
Current protection tripping power, W: 800+/-200
Maximum total capacitance of capacitors*, µF: 10000


59$
The +/-48V and +/-53V models are available.
other options are available on request, selectable in multiples of 5V.
Autostart module by audio signal +10 USD
Designed for 2V RMS audio source.

shipping 12$

*No CE certification, shipment to some countriesi may be complicated!

Replay to

Hello everyone,

It took a bit of time to messing around today to get this to work, so I thought I would post (details may be specific to the STM32F4 microcontroller I am using).

But I do have a question also for any STM32 experts at the end.

On the STM32 platform the if you pick a external crystal with frequency that is a multiple of the 96kHz then you can, unsurprisingly, get 0% error between desired and actual I2S frequency. 24.576MHz / 96kHz = 256, so 24.576MHz seems a good choice being a standard frequency with lots of options of low-cost crystals.



USB needs exactly 48MHz clock, fortunately 48MHz / 96kHz = 500. Below is a solution that gives exactly 96kHz for I2S and 48MHz for USB.



Question

What is I2S_APB1 CLK and why does it having a value of 147.456MHz make everything work so well? I mean, this is 6x the crystal frequency and 1536 x 96kHz but why is this the required value for the I2S_APB1 CLK?

Hi Everyone!

I am opening this thread in order to present you a project i am working on since March 2014:

Archphile - Yet Another Archlinux Based Audiophile Distribution for Raspberry Pi and Udoo Quad

Summary:

Archphile is an Archlinux ARM/Mpd based distribution for Raspberry pi model B and Udoo Quad, targeted to users with USB DACS. Usb disks.

• performance as default cpu governor (without overclocking)
• recompiled mpd 0.18.11 (mpd-archphile) based on mpd-light from AUR – niceness is set to -19 and lots of mpd features are disabled in each version (press mpd -V for more info)
• latest firmware using rpi-update for the Raspberry Pi version
• ympd 1.2.2 web interface.
• usb disk/flash automounting using udevil.
• dchp enabled by default
• reachable with url http://archphile.local if zeroconf is enabled. In any other situation you can find the ip from your router
• samba/cifs/nfs support – you have configure /etc/fstab according to your own needs by modifying the sample lines
• default credentials:

username: root
password: archphile

• various webradios taken both from Volumio github and some added by me.
• mixer is disabled by default. Use your amp to change the volume level. Ensure that system level is set to 100% using alsamixer command.

Supported devices:

- Raspberry Pi model B
- Udoo Quad (and dual with some extra steps)
- Cubox-i (unofficial support as I don't own any of these devices)

Details:

Archphile is in fact an ArchlinuxARM based distribution that uses MPD and a nice web interface for it, named Ympd:

Arch Linux ARM | Arch Linux ARM
Music Player Daemon
ympd - MPD Web GUI written in C, utilizing Websockets and Bootstrap/JS

I have created a repository for this project:

Archphile - A Linux Audiophile Distribution - Repository

In this repository you will find two packages for mpd, one with minimal dependencies (installed by default) and one with ffmpeg support. You will also find ympd and some extra packages that help in the configuration of the whole system.


Why I made Archphile

The answer is simple: for fun!

I have been a linux user for many years (especially used debian unstable and Archlinux until today). What I really like in Archlinux it's the whole K.I.S.S. philosophy, that's why I created archphile with K.I.S.S. as a guide.

Ympd, is not a system web interface. It's just a web interface of mpd. You cannot configure stuff through ympd. You need ssh access and you have to configure some things yourself (with the most important being the NAS configuration). For this purpose, I have written some guides which I keep them up to date:

Archphile - A Linux Audiophile Distribution - How To

I have been asked to add features (ex. Shairport, spotify, nas configuration through web interface) many times until today. I will not do this and the reasons are:

- I am not a software developer and I don't have the knowledge to create a web interface or port YMPD and change it to my own needs. Even if I were, I would not make one. I prefer to choose and adapt existing open source project that does the job right.

- I really don't like automations. I prefer to configure my NAS one time by editing one file and forget it. From my experience, this philosophy has been proved the most stable in the world of linux.

- I know that spotify is nice, I also know that Shairport is very useful for some of you, but my intention was to create a very minimal configuration, with the less software and services possible because I believe that simplicity and low resources are two of the keys of the computer audiophile world.

Just plug the ethernet cable (or configure wifi - I always prefer ethernet) or the usb disk, connect the dac and the embedded device with a usb cabel, choose your flacs through ympd interface or any other mpd client and listen to music!!


Screenshots:

1. ympd - the mpd web interface




2. Ram/cpu usage in Raspberry Pi with 24/96 Flacs:




I really hope that you will enjoy Archphile!

Cheers,

Michael

Back in April 2022 I bought 20 pieces of TIP3055 and TIP2955 transistors from Mouser US.
Last week I opened the packaging - I wanted to select and match 2 pairs of devices.
To my surprise, transistor tester detected different pinout on them.
As with most BJT/Fet (except laterals) TO-247 devices, pinout is supposed to be B-C-E.
But here I see B-E-C.
Also Beta measured shows value of 12. Datasheet shows minimum Beta as 20.
Real TIP2955 I checked usually show value over 60-80.
I checked random 5 transistors from the batch of 20, and they all show the same thing.
TIP3055s seem to be 'normal'.
What this world came to? Even Mouser sells fakes now?

Mouser refuses to replace or refund them, as '90 day return window already passed'.
Buyers beware.

Hi everyone,

This might be a strange question, but does anyone know which NAD amplifier was used in the 705 receiver? Similar to how the 3020 amplifier section is in the 7020 receiver.

I'm asking because I want to troubleshoot a 705, but the schematic available on HiFi Engine is so blurry that I can't make out much of it. I was hoping to find the schematic for the specific amplifier model used in the 705 and use that as a reference instead.

Any ideas would be greatly appreciated!

Cheers

For a while I've been using Virtual Machines for my audio/media, but (unsurprisingly) things often work better or more easily if run on the main/host system. So I'm going to set up an actual/real machine instead: software crossovers and equalisation, playing local and internet-based audio and films plus browser content.

More controversially (for me) I'm thinking of moving back to MS Windows for it. Increasingly, sources include online/streaming services, whose linux apps might be second-rate or non existent, and their browser-based alternatives less functional (there is 'wine' but again, for a dedicated machine things would be better running natively). TBH I don't really like Windows; the phoning home, push updates, bloat and less control of one's own PC, but it would probably be acceptable for a hobby machine.

It looks like I could still use applications like CamillaDSP and REW on windows. What other EQ/DSP/crossover type apps should I consider? Are there any audio challenges with windows that I need to know about?

Thanks,
Kev

Hi all. Bought a KorgB1 from the store on a whim, and have been hooked since.

Hi,

my 2 way faital 15pr400 and hf108 measure nearly perfect after dsp equalization (camilla dsp).
Pic shows mesaured them individually and both the same time.

The response is worse, when measured both the same time (blue line). Does it make sense to equalize it to flaten the response?

What`s the reason for the blue response? The mic was placed in the middle when measured (runtime difference was zero from left vs. right).

I wonder if some one has experience with this or similar deck and could give me advice. I need to recap GX-270D main caps.
It has dual cap 3,5uf and 1.5uf 15V (dual cap), I believe this is for the knob controls and rewind motors and they are a bit weak towards end tape rewind/forward.
Than it has 330uf 160, I think this is for the main motor (?). The motor runs fine, but hums.
Than there is a big dual cap, it reads 4x4 250V. I have no idea what the 4x4 is in uf. (2x 4uf maybe?). I think this is the main power cap for the electronics.

330uf cap I have spare, but I don't know what the 4x4 value means on the other one. Also the 3.5uf and 1.5uf can be found online but they are stated as "run/start capacitor". So I don't know if these are somehow different to a regular caps, though I can't see how.
Any tips would be appreciated, thanks.

Hi everyone,

My question is one that isn't about inductors, but CHOKES, specifically inductors used for blocking the passage of high-frequency signals into/from different circuits. Those of you who know exactly what I'm talking about will probably say "Say no more", à la Monty Python. So, my question about chokes is this: If I wanted to make my own choke for power supply purposes, specifically preventing... I'll come back to this... As I'm writing this I realize just now that I am unsure of WHAT exactly is being blocked in what direction. Anyway, let's suppose it's the 60Hz from the AC line, which is coming from the transformer. I'm not sure how to decide how much inductance I need to have, but I know it has something to do with the impedance of the power supply circuit itself, but that depends on the load that it's supplying, right? I believe there's an actual mathematical derivative function (I could be talking up my father Jack here)that states that the current drawn by the circuit relates to what inductance can be chosen, or something to do with current... I'm not making much sense here, but IF I tell you all that my load will draw 2 amps, what kind of choke do I need to make to cut out the AC? To what degree you may ask : well, I'm not sure, I guess that in itself depends on how big I can allow this inductor to be... About 3/8" diameter by one inch long, or so?

Now, earlier I said, " specifically preventing... I'll come back to this... As I'm writing this I realize just now that I am unsure of WHAT exactly is being blocked in what direction."
In my application,. which is a power supply for a tape deck that I'm building, we all know that the bias circuit oscillates at very high (not VHF, I'm just using the term casually) frequencies, in the order of 80 to 150kHz, typically. So, I may be wanting to prevent the leakage of this frequency, however small it may be, back into the power supply and muck things iup in there, I'm not sure. Is that possible, would that risk happening? I am concerned about creating. resonant circuit by putting the choke in an L-type circuit next to the final filter cap... but I realize that I'm going to put the same types of chokes on both amplifier cards, and that would also complete this resonant circuit...

Am I overthinking this? your thoughts are appreciated. I wish I had a schematic, but I do not currently have one. Typical transformer, linear, transistor-Zener diode regulated topology.

Thank you all for taking the time to read my mini novel!

I need help with my akai that has the sagging counterweight. I dug out the old rubber but can't get the screw to come out, I think it's stuck. The little plastic tab underneath the little stub for the weight broke.

Hi,

I am in the early planning stages of a listening bar business. After looking at a few buildings many of them are too open (potential problems with neighbors) or acoustical nightmares with tiled floors and lots of glass and of course low ceilings and only parallel surfaces.

So unless we find a better space we may end up getting empty land and build our own building. Then I can make a space (150-200m2) with non parallel surfaces (golden trapagon?) and a sloped and/or vaulted ceiling. Also the room will be quite sealed without many windows and double door entry.

I am by no means an expert so I would love some opinions on the following:

1. In a regular room people use absorbers, rugs, curtains, furniture..... Is that also needed when the shape of the room is optimized? Or can a room sound good with only hard surfaces?

2. What is the best wall for early reflexions? Would rockwool sandwiched between a brick wall and concrete ventilation blocks be a good and cheap option with a mix of absorption and deflection?

3. What would you do if you could build a large listening room with a small budget?

For a very large public listening space I am looking at a forced stereo image since only a few of the listeners will be in the sweet spot where 2 channel has a good phantom image.

I would like to use 5 speakers where the center speaker only plays what L and R have in common, the middle pair plays L or R and the outer pair has the content unique to L or R boosted by a adjustable amount.

I looked at my miniDSP flex 8 and don't think it can do this. Are there existing analog or digital solutions that do this? Has anyone tried something similar? I see some older info on doing it with 3 channels in stead of 5 and often the center channel is just L an R summed instead of only the content common to L&R

Here some info for repairing your Even Opal.

I have a set of Alpair 7s in my Frugal Horns that came in a flat pack from planet_10 hifi: FH3. I have been using them for about 11 years or so and really quite like the speaker. One of the drivers is experiencing some rubbing on the voice coil and am looking for a replacement. From my limited research, some folks are suggesting the Markaudio Pluvia Seven HD 4 inch which seems in my budget range.

I do live in Canada which can limit some options. What does the knowledge base recommend these days?

Thanks.

Back by popular demand! Please note that it can take a few months to get everything. Supply chain issues have made it take longer. Some have wanted different parts for that reason but the popular opinion still remains on preferring the very nice quality ones originally included.


5x20mm fuse option added for Euro buyers

So over the years people have asked about the old version, made by someone else.

It's probably time for an updated one. This one is a bit different. You may notice it does not have following capacitors after the choke. I have tried both ways, and my preference is without the following X2 capacitors. Also the capacitors prior to the choke are not varied in size because overall capacitance is more important - and they won't randomly resonate with each other.

The other major change is the addition of bypass resistors for the chokes. These don't ruin the filtration, but they do a good job of quieting the chokes that can get excited by different combinations of things on the mains.

Click to expand...

View attachment 1043981

Gen1 w/comoco's


Here's how it is different in settling time from the original.


Here's a comparison between resonances.

*2oz copper PCB (1oz is standard)
*Weco 983ZD terminals, copper alloy and can accept 2 wires for daisy chain. These are also safer, particularly if you use solid core wire that otherwise likes to make cold solder joints you can't see.
*X2 rated capacitors for safety, 4x 0.47uf. They are alternated for CFC (capacitor field cancellation).
*Discharge resistor for X2 capacitors
Coilcraft Comoco choke w/fuse or Bourns 8120/8121-RC choke w/o fuse & 15/16A/20A() max sockets
*Fuse clips are beryllium copper 3AG & 5x20mm options
*120/230v operation (parts & pcb)
*Mounting holes are sized to work nicely with M3 screws and standoff kits
*Size: 2.25x4.25in

Click to expand...

The Weco 983ZD are preferred terminals, but not always available as individual sale. For this reason I'm going to include them in the price of PCB, so that I can meet min order requirements for them and save everyone the shipping.

Price: $14ea ($10 per filter board, $2 per Weco, 2 needed per board)

Shipping: $11 US, priority USPS box
$20 CAD
$22 General international padded envelope (prices may vary due to a crazy world)

If ordering over 4x boards there may be an additional $10, depending on destination.

Need 32 filter board commitments to order.

wcwc 10
bigaudioscotto 2
marxist 4
zlib 2
arthur 20
yoaudio 3
rongon ?
Mark Johnson 2
Windcrest77 2
northpaw 2
CritterSoft 8
danbmellow 6
audiotony 6
JDinBigD 2
Alfi 4
ElArte 4
brik 4

Click to expand...

Hi All,

since reading about Purifi drivers, I'm thinking about using them in an open baffle system.
Those drivers show fantastic test results from @HiFiCompass , erinsaudiocorner.com etc.

Most of the parameters should be very nice for using them in OB systems: high xmax, very low distortion, even during high excursion, very low intermodulation distortion ...

Only downside I would see is the low sensitivity of some drivers, especially the X-Versions with the highest xmax. Of cause this is logical, but depending on your open baffle design, the sensitivity on the lower end can be - due to the dipole cancellation - even much lower than the value in the specs.

Now I'm asking myself, which could be the optimal Purifi driver for such an system for the midrange.

Actually, there is of cause a dedicated midrange driver, which looks very good, however, from the specs, in terms of distortion etc. the NAA-Versions of the PTT6.5 are on the same level.

So which driver would be the best choice then?

This is my setup at the moment:

Acoustic Elegance Dipole18 20-80Hz
BDDesign BD15 (Beyma OEM) 80-800Hz
Scanspeak 12MU 800-2.100Hz
Mundorf 25D1.1 2.100-20.000Hz

All crossovers, room correction etc. with Acourate FIR filters.

The current system is still in a kind of long-term beta test phase, so somehow never completely finished. 😉

Why this choice of drivers? Because I already had them available 🙂 Especially the 15 inch might not be the optimal solution, but basically it works great in the used frequency range, keeping a good directivity for the overall system.

The whole system works very well at the moment, however, for non-technical reasons (WAF among other things 😊) I would like to downgrade a little bit. 3-Way would be fine, perhaps later I will add a subwoofer for the lowest octave.
So plan is to replace the BD15 and 12 MU, Change the xover frequencies and use a Purifi instead.

The Dipole18 should be able to play much higher than in my current setup, the Mundorf can be used a little bit lower, than the above mentioned cutoff.

I think the Purifi could play somewhere from 300 or 600 Hz up to 2000Hz


I would be interested in

• your suggestions
• your (listening) experience (especially PTT6.5M and PTT6.5X-NAA)
• feedback in general
• any valuable comments

Thanks and best regards
Matthias

(On the picture the speaker is not at the listening position, as we are rearranging the living room at the moment.)

Hi guyz ! 🙂

I have 4 sub AMP plate and now I have a humm sound because 2 plates was un the same AC plug and no humm but 2 other was un different Ac plug on the Room and I think it created Ground Loop. Anybody have a real solution !?

• I try AUDIO Ground isolator = more humm 🙁
• I dont have third pin AC mass Ground on any amps on this system.
• I try to add coupling cap 0.1uf or 3.3 or 15uf = not Working

Thanks in advance for your help 😀

nicK

Hello

I work with cassette decks mainly in my shop and have seen an influx of service requests lately.

What cassette decks are you guys using?

Paul

I recently acquired a MAS (Metaxas Audio Systems ?) Marquis pre amp, but without the accompanying power supply unit, and other than it requires dual power in (confirmed by their being two three pin connectors on the back, with it looking like each powers a separate channel) - I am struggling to find any information on the design input voltages.
I believe it is a Mk I, although purely on the basis that it doesn't have a Mk number !

It looks nicely put together, and from the limited amount I can find online, is a tempermental, but potentially very capable, unit. I am therefore keen to try and build a power supply for it, and at least get it up and running.

Any information anyone has on the DIP switches used for the phono section loading would also be appreciated.

Thanks in advance for any help provided

I've been following the forum for several years and am interested in using an Rpi/OrangePi system to play SACD.
Thanks in advance!

Up for sale Twisted Pear Audio Retro phono preamp. Those are fully working, populated boards for use with MC carts. Neutrik XLR in/out panel mount connectors included. $75 FF Paypaled ships it to your door - lower US only. Thanks !

New member here. As explained in my intro I've been working with DIY audio since my teen years but have never found need to raise questions at a forum. Very difficult for me to keep it short especially as the application is unusual. Jump below the line to skip the description of the system and problem to specific questions.

I have an acoustic grand piano with a current model PianoForce player installed. Like other modern players it can play the instrument to synchronized audio.

The accompaniment has evolved since the installer of the unit originally mounted one AR "Powered Partner" to the underside.

Until recently it had two additional powered loudspeakers very similar the the ARs, an excellent Reel 10" powered sub plus the original AR now lying on the floor just behind the lyre (pedal assembly).

We were generally pleased with the sound--especially when near the piano--but since much of the listening done upstairs (the piano is in a very large rec room in the basement beneath the common area of the house) the lack of acoustic power in the midrange became apparent particularly with male vocal in the natural (not Steven Tyler) register. While it is certainly source dependent vocalists can sonically appear to be sitting on the piano bench. The general layout of the loudspeakers was designed to enhance this effect

So, I've been on a months-long search to find something--anything to use instead of the Powered Partner. Utter failure trying to find a scaled-up version of the Powered Partner with a 6" or so main driver. The shape (like a stage monitor) is crucial when used on the floor. A stop at a good pro audio store while visiting a city found a Yamaha (8" driver) suggested but I wasn't willing to plunk down over $700 for an experiment when the person I talked to said, "You really need a twelve-inch driver to convey the human voice."

Since I'd asked for something to essentially use in the human vocal frequencies of about 100hz to 2kh that statement about needing twelve-inch driver kept haunting me.

The piano easily overwhelms the present accompaniment. The amplitude of the piano compared to the accompaniment is very similar according to the old Tandy db meter and iPhone app (which are in very close agreement on weighted scales). My ears, meters and experience told me that I was missing volume in the accompaniment.

So I installed a Peavey 12" floor monitor from storage and direct connected through an old Soundcraftsman amp. Result: excellent sound--upstairs; not so good in the space with the instrument. Upstairs we agree--no louder than before--but "fuller." Exactly what I'm going for. In the rec room however imaging is no longer as nice and the thing is just too large. Another brand of 12" floor monitor at hand is even larger and more poorly proportioned for the applications.

I've been considering a custom build for some time and have been searching for driver(s). Remembering early years I wondered, "Does anyone make a good quality, large whizzer cone?" under the idea that such [should] produce an excellent driver for vocals that naturally falls off at higher frequencies above 2khz or so but potentially flat down to near 100hz. I've been using the Thiele-Small parameter calculator so frequently that I remember why my first computer program was done to do just that on a TRS-40 in 1983. Beyond what appears to be an ideal candidate as a whizzer, I've been using design parameters on drivers from 5" - 12"

The below is based upon the above. I'm very much open to alternatives from experience or theory!

--------------------------------------------------------------------
Loudspeaker for "vocal" element to accompaniment system for modern player piano
general design: sealed in the shape of a blunted wedge (stage monitor like); self-powered (ideally)
driver(s): "full" range--desired flat frequency range: 100hz-2kz (note 2khz NOT 20khz!)
special note: commercial loudspeakers attempted are an Acoustics Research Powered Partner (insufficient volume) and Peavey 12" floor monitor (obtrusive with poor transients/imaging)

I found the Eminence Legend B102 seemingly made for my specs. I found it while specifically searching for whizzer designs in a larger woofer. Searches here and elsewhere lead me to believe that it's at least a "good" loudspeaker. That said, musical instrument loudspeakers don't necessarily shine when it comes to the human voice and its transients. Any comments from those who have heard and used it?

My principle alternative to the above [seems] to be an array of smaller drivers. The only sonic advantage I can envision is increased accuracy. There is however a potential and significant aesthetic advantage as it be lower in profile (if not smaller in volume) compared to using a 10" or larger driver. I can also envision a situation similar to the present where I lack acoustic volume despite sufficient amplitude. Any specific driver suggestions should I go this route? I have a reasonable budget but consider things on the order of 4@$600per beyond reason. My ears are good but not that good.

Thanks!

I have a decent soundcard (focusrite scarlet) and with REW was doing some measurements on an interstage transformer and seeing more distortion in the 60Hz-1Khz range than I expected. So as a control I popped in a Lundahl LL1676 line input transformer and still saw some really high harmonic distortion numbers. In this case it's operating as a 1:0.5+0.5, balanced in and balanced CT out, using 1K ohm source resistors on each leg to simulate some tube Rp. Most notably this was only at about 1Vrms and no DC current, so should be nowhere near any kind of core saturation.

I'm perfectly expecting to see rising distortion at low frequency and rising power. But I really didn't expect, for instance 0.1% 3rd order harmonic at 300hz with just 1Vrms in what's supposed to be a fairly well regarded line input transformer and phase splitter. I did some more testing and it's a little suspicious that a large high power bifilar interstage, a lundahl amorphous core line input, and an off the shelf pro audio balanced isolator box all seem to have similar total distortion levels (around 0.5% in the 20-30Hz range, gradually dropping into the 1-2Khz range) at a low signal level of 1V rms. They do all have very different distortion profiles in terms of how much of each order and how they roll off though.

Has anyone else done this kind of distortion vs frequency sweep on transformers? The very few transformers that show a THD vs frequency graph, like the Jensen input transformers seem to show vastly less harmonic distortion in these areas and power levels, like it should be closer to 0.001% than 0.1% in the 100's of Hz range. Does the lundahl just have 100 times worse distortion than a typical Jensen, or is there something else going on that I'm missing.

I read from "Designing High-Fidelity Tube Preamps" and learned that LC filter may need to be "damped" by adding resistor in series to the choke, and multiple LC filter (e.g. LCLC), although can achieve a much higher filtering, may lead to multiple resonance frequency, which even under audio frequency, may still cause stability problem like motorboating. Nevertheless CLC is frequently used, at least, for the output stage as RC simply consume too much power to provide adequate filtering. I want to explore how to properly implement CLCLC filtering but seems there is little mention to the multiple resonance frequency and how should it be damped. I would be appreciated if you can share what you know on this topic and any good materials discussing about this.

I am looking for a 2nd hand external sound card (ADC) for measurements. 24 bit 196 kHz. EU seller preferred.

Sadly it is time to move the TABAQs on to a new owner so I am offering up these "short" versions for sale to one lucky buyer! It's been a great journey and experience building and using these amazing speakers. Thank you for all the inspiration and help on the forum.

I have listed the sale details on Ebay UK. I am open to offers on price, and viewing and collection is available in Chichester (UK.)

https://www.ebay.co.uk/itm/356122161155

Simulation details are in Bjorn's thread here

I have 2 pieces of JBL 2404 H drivers for sale. They are with original diaphragm and play exceptionally well.

Price, EUR 350.- for both. Shipping costs are added.

I thought I would kick off 2019 with this thread about dipole loudspeaker design and construction. Specifically, how to create a loudspeaker having a dipole radiation pattern across as wide a frequency range as possible, when it might make sense to abandon this goal in favor of some other criteria, and the justification for employing the "full range dipole" concept.

One area that has been neglected (in my opinion) is what is happening to the rear of the loudspeaker. In an open baffle or dipole speaker, there is sound emanating from the rear that ultimately reaches the listener via the room and this is just as important as what is coming out of the front of the loudspeaker. So when I talk about a "full range dipole" loudspeaker I mean to emphasize that the front and rear radiation pattern should be as similar as possible over all frequencies.

I have been working towards these goals for a few years now and have built and dismantled a few test systems to try out some different approaches. I hope to share what I have learned, why I prefer this type of loudspeaker, and when it might work well or not work well for audio reproduction. I hope that others will chime in with their own experiences in this area so that we can all learn from each other.

I thought I could put down some thoughts into a few posts, but ended up creating a pdf file to kick off the topic (see attached). I would love to read about what systems you might be developing along these same lines and get your feedback about my approach to such a system.

I was told to post here first? 😁

So I'm thinking about a low-power multichannel amp inside a PC. The Sure/Wondom KAB9 is my top choice at the moment. On-board CM6206 chip for USB-to-7.1 makes this project crazy simple. Just need to work out mounting, power, and speaker connectivity. Wondering if it's feasible to use the PC's own power supply. Two concerns here are it being ground-referenced and that it would be exactly 12V which is right at the lower limit for this module. Hopefully it'd start and operate reliably at this voltage.

RM

Hello,

there is two school with simplified talking about dome tweeters : to make it simple, at iso THD & T/S, two drivers will sound the same if the same spl curve.

The second one is it will not because each cone material is sounding different (Hificompass, Troels Gravsen for instance).

I'd like to know if the ceramic coated tweeter is making it to sound different w or w/o this coating. Some say it is just for the looking or against corosion (magnesium dome ?)

Does is sound alike a berylium or a 100% ceramic one ? Some talk about a more relaxed sound with those last both?! As far i know, the motor design seems much more important in the result of micro dynamics at those frequencies.

We don't care, i.e. the spl curves matters first ? Purchase a DSP or EQ any cheap good tweeter with good THD enough (SB26 CDC for instance) if you like white domes and sleep better ?

You may enter your choice preference and experiences in a post about a material if you voted YES. You can also input why according your experience a NO makes sense.

Thanks

I came home today with this beautiful, one owner, and consecutively numbered pair of Heresey 1s. Year is 1981, and they're 100% stock. I've read a lot over the years about these. Positive, and negative. And I can hear some of both in these, but luckily more positives. I fell out of listening for a while, and had been running these Polk RT55i (2x6.5" and 1x1" soft dome) just to keep something hooked up. They worked, that's about it. As I'm getting back into the hobby with valve amps, I wanted to have nicer speakers again. Something more transparent, allowing me to really enjoy/voice what I'm building. Last nice pair here were vintage JBL L100s, and I wanted something similar, but not the same. I've been interested in finding some Heresey 1s for some time now, so when I saw a pair this nice, for 1/2 what they usually sell for, I had to jump.

Ahhh...I think these fit the bill, and they're so much better than the Polks. I was pleasantly surprised finding they excel exactly where I had hoped they would. The bass control, clarity, and of course sensitivity...I'm hearing new things, and things that formerly lived only in my headphones. Amp currently hooked up is an el-84 PP I designed last year. Eico iron, 10w, and it finally sounds "alive". I'm running 2.1 with a 100w powered 10" Episode sub, crossed over right around 45hz. I think the Hereseys need stands, although I see many different heights people use. But otherwise, what are some other items of importance? Checking/replacing caps, fill type/qty.? Any user experience appreciated.

Thanks all🙏

Loren

Hi 🙂

Those are the titanium "candle type" matched pair 2a3 with quality control from Grant audio Canada.
Between the price and import duties to Europe I paid 540eur (order copy to prove available if course)
They were a stock pair that I never used except 5 minutes to test when they arrived and release Grant audio that all went fine and tube were ok perfect.
I ask 320eur plus shipping or best offer if fair. Thanxs for looking

Hello,

first of all, I don't want to violate any rule on this forum. So, dear admins, please remove this thread if I do something wrong.

For years I am using Apple computers and I like them. But there was always the disadvantage that there is no loudspeaker simulation software that was made for macOS. I know, you can run the Windows stuff with Parallels or CrossOver or whatever. But I never liked these solutions. Besides that I love my iPad and again, there is no loudspeaker simulation software for it.
Thus, a few month ago I thought, let's change that: I made an app called AENEAS.
AENEAS can simulate several enclosure types:
- Infinite Baffle
- Closed Box
- Vented Box
- Bandpass 4th order
- Bandpass 6th order
For the simulation AENEAS needs the Thiele-Small-Parameters of a driver. In the 2nd step the enclosure is selected. To make the design of an enclosure quick, you can choose from some standard alignments given in the literature or you define everything yourself.
From your input AENEAS builds an equivalent electro-acoustic network and runs a SPICE simulation of it. Therefore, I have implemented a light-weight spice simulator, which I programmed myself. You don't have to run an external tool.
Currently AENEAS plots the following simulation results:
- SPL Magnitude @ eg in 1m distance
- SPL Phase
- Impedance Magnitude
- Impedance Phase
- Excursion @ eg
- SPL output driver and port
- Max. SPL
- Max. input voltage
- Max input power by amplifier
- Group Delay
- Transfer function of enclosure only
You can run several acoustic networks in the same project. That makes it easy to compare how the driver behaves in different enclosure designs.
A project can be saved and loaded. Again to make life easier you don't have to type in the TSPs parameters again and again. Once you entered them, you can save them in an XML-file, one file per driver. Thus, you can later load them again or send the file to a friend how wants to use that driver. The project files can be exchanged, too.

I know, there are many other things that could be implemented. But for the first release I wanted to limit the features, else it gets easily messy.

Yesterday I released version 1.0.0 for macOS on Apple's App Store for 5.99$.
https://itunes.apple.com/us/app/aeneas-enhanced-numeric-electro/id1189221756?l=de&ls=1&mt=12
I am now working on the iOS cross-build which is currently in beta status.

Besides that I've a roadmap to add more features to AENEAS like Passive Radiators, Transmission Lines, passive and active crossovers etc.

I hope some of you will like it and are going to use the app.
I would like to offer some technical support here and would like to hear from you if you find a bug.

Raphael

Subwoofer question. Can i drive 3 woofers, 8 ohm with a Aiyima A07 amp. Does somebody have experience with it?

I would like to make a simple OTL.

Does not need to have lots of watt, something up to 5 watts is enough.

I would put small fullrange drivers in series like 12 drivers with six ohms, 72 ohms alltogether. If it helps impedance matching. Maybe 15 ohm drivers if I can get some.

High output impedance of an OTL amp would make it automatically work as a current driven amp?

I would like some Smps as power supply if possible.

Would an electrolytic in the output help to protect the loudspeakers?

I just do not like copper graves like big transformers. And good ones are expensive.

Hello everyone, I got my Acoustat Spectra 22's over 20 years ago, used them until we moved in 2017, and then had them stored in a fairly dry basement.
Now I tried to reconnect them and one of the speakers sounds fairly dull, compared to the other. It lacks any bass and is significantly quieter than the other speaker.
Another thing I notice is that the LEDs on the back glow very faintly, I can only see them when I switch the light off. This is the case for both speakers.
The MK-2123s seem to be the pretty late model with the 15V AC wall transformers. I am using an aftermarket 15V AC transformer.
I opened up the MK2123 this afternoon and got this:

So the 470 Ohm (?) resistor looks pretty cooked, no idea if the Zener diode is still working. Obviously there was a pretty high current running here, I wonder why. Anyone has a clue?
I will replace all electrolytic capacitors on both speakers of course.

Cheers, Robert

Hi,
Simon here!
I love to tinker and attempt to repair anthing given to me
I`m usually into more electro-mechanical, like VHS machines, or Cassette players, but I do also like to have a go at anything.

I seem to get a lot of retro computers and stuff to repair - due to me seeming to have that reputation at the Retro Computer Museum, where I am a team member.

My AV stack consists of: (all Sony)
Sony LBT 905D stacking seperates
200 disc DVD player - DVP-CX850D
VHS machine - SLV-E80
Laserdisk player - MDP-850D
Amp - STR-DB930
DAT Player - DCT-690
And due to it was designed to fit in a stack..
Commodore CDTV
And a Checkmate 1500 + retro computer case with and Amiga 3000 in!

as well as a PS4 sat between them!

ALL listed and show, I have aquired as non-working, and fixed!

Hi,

I'm looking for a horn loaded solution, 50 to 350-400 Hz to suit 15" driver.

Having looked around it seems to 'hear' these things is difficult to realize - although I did enjoy La Scala, despite the LF shortcomings.

A straight horn is not going to cut it, needs proper output down to ~50 Hz so that a sub is not mandatory, folded horn is an acceptable compromise.

Based on many hours of 'reading' I have shortlisted the following:

• University Classic or Dean
• EG Beck California
• 2x Quarter Pie - 2 cabs side by side, straight edged version with larger deflector and stacked side by side 'on end'
• La Scala or Peavey FH-1 with 'bass reflex add-on'
• Karlson 15
• Onken W (?)

Drivers are Faital Pro 15PR400 - specs attached, (4x at hand) driven by ICE 125 DSP amplifier/XO (at hand).

Room is 170 M3 with 2.7M ceiling. Concrete floor. Walls and ceiling are timber stud frame with fiberglass (batting) insulation and 10mm drywall.

M/HF is 2" CD on Fc 200 Hz JMLC horn (at hand), crossed ~350 Hz, 750 mm diameter. The 200 Hz horn center doesn't need to be at 'seated ear height', all above cabinet heights are close to okay.

Looking for real-world advice to assist with narrowing down options, subjective or objective, but asking for real world experience, thanks.

Cheers

Hello,

I'm modifying an old power amp, which has a very sophisticated speaker protection circuitry 🙄 To make things easy with my modifications, I would like to place a relay at the amplifier output.

Now, I have found a pair of S202S01 SSRs among my parts and I'm wondering if it would be reasonable to use these 😕

Does anyone have experience with SSRs as speaker on/off switch?
Or do you see any problems using these (apart from heat dissipation)?

Best gegards,
Frank

https://www.eighteensound.it/media/...dfNzcxXzE4X1NvdW5kXzEyXzJfV2F5c192MS5wZGYiXV0

Above they use hd1050 .. I want use nsd1095 instead.. how do I best simulate to arrive at a new crossover schematic ?


https://www.eighteensound.it/en/products/hf-driver/1-0/8/HD1050

https://www.eighteensound.it/en/products/hf-driver/1-0/8/NSD1095N

I have a 1957 Phillips Receiver.. there's no option for restoring the record deck and the we will soon loose analogue radio.. (bluetooth streaming I know about)



Here's it after my restoration.. replacing the leaking caps and installing a shunt for the modern high wall voltage.
Login to view embedded media
However it doesn't get used.. and I was thinking that an option could be to plunder its components and build a 1957 styled/voiced guitar amp which is likely to get more use. I've got a load of ply left.

I'm just trying to consider if this is worth it..

So I got a fun one. The repair of an Ampeg SVT-3 Pro output stage I can’t wrap my head around. It came in with a rapid clicking output relay. A quick measurement showed the output had +65 volt on it and the relay repeatedly disengaged as protection. I suspected the output MOSFET’s, but they test good (tested on my Peak Electronics DCA75 pro). I also removed three on each side, but the issue remained. I continued to test all surrounding transistors and they all came out fine. Measured diodes, zeners, caps, resistors, all good. Voltages check out as well.

There’s a balance trimpot between the gate rails and when turned almost fully counterclockwise, the output offset goes down to milivolts, but it can’t amplify the positive part of the soundwave anymore. I don’t fully grasp the function of this trimpot or the workings of the TL074 in the feedback path.

I appreciate any fresh perspectives, ideas or similar experiences. Attached is the schematic.

I'll be in Hong Kong for a couple of days. Any shops for diyers you could recommend?

Best,

John

My portable bluetooth speaker has a few shortcomings which can be remedied with some filters, however I need a DSP board for those. After digging a bit, I've come to the conclusion that there aren't a lot of options when it comes to DIY DSP boards, not mentioning expensive contained modules like the ones from miniDSP of course. So far, I think my options boil down to:
- smt32F4 family of boards
- adau1787 from Analog Devices
- FreeDSP (sadly not optimal for sourcing parts to do it myself is difficult where I live)
- Potentially an esp32

Now the last option is promising. I'm not sure about it, but I've seen that there is a DSP library for the esp32 as well as DSP with Faust.
If anyone has any knowledge or hands on experience, are these reliable? Is it potentially too much of a headache for no reason in the end?

Say a DAC that accepts 110ohm digital input (i.e. from transport) - what is the typical input impedance? Is it 110ohm or something very high? Thanks.

For sale is a set of Miro PCM58P Dac board with PSU.
It runs on a PSU with rails +/-12V and +5V, which is included in this sales.
i2s source (Amanero USB-i2s, JLSounds i2soverUSB are some examples) to feed it in order to play music.
Look at the info in the thread to see the PSU requirements and information on the DAC board.
https://www.diyaudio.com/community/...s-input-nos-r-2r.354078/page-232#post-7085999

Board fully populated with good quality caps eg. Elna Tonerex, Nichicon KZ, Wima mkp and Kemet mkp film caps, Panasonic acrylic caps. all the signal resistors are low noise non-magnetic resistors with copper leads, good quality Nextron IC gold plated contacts sockets. Packed with high quality components.

This board also have u.fl connectors installed in case you would use them.

This is one of the spare board that i have built. All components, including the PCM58P Dac chips are bought brand new. They are populated to commission the board.
Each board has two new PCM58 chips.

Important Note : I ran out of op amp. There is no op amp provided in this sales.

Some members said they prefer PCM58P than the PCM63P. It is up to individual and you have to try it yourself.
I built two boards and will keep one for myself. I would like to say that you would not be disappointed with the sound.

Price is $120USD, including shipping registered worldwide. Paypal Family and Friends only please.
Check my track records in this group. Shipped 50+ packages to members here without a glitch. All received and happy.

Hello! I'm new to the forum and I'm hoping someone may be able to help me. I have been trying car audio amp repair but I'm lost at the moment.
I have 2 Monoblocks with different issues.

1. Concrete Audio 2k
Protect mode at 13v+ although rated up to 16v
At 12v, gain all the way down, no input, and with a speaker connected (I have tried a few different speakers and all do the same), starts normally then makes a loud pop every 3-4 seconds and flashes protect light
Does not happen with nothing connected (12v), audible click, power light and fans running, no protect

2. Soundstream XXX-6500D
Turns on with power LED and no protect, fans run, but no output to speaker terminals
Tried multiple speakers, tested with multimeter (any settings to try? I may not have tried correct setting), multiple RCAs, but only tested with 12v. This specific one has ratings at 13.5v, 14.4, and 16v but my other XXX-6500D has at 12v-16v.
Would 12v vs 13.5v cause this?

As of right now I would prefer to get the Soundstream working sooner than the Concrete Audio amp as I would like to install the Soundstream in my setup

I have a variable power supply that can go up to 30v and 3amps, a component tester, multimeter, and an oscilloscope but I am a bit confused on where to probe, what settings I should have, and where I should ground the probe or if I shouldn't use the ground lead.

Any help is appreciated and if there is anything someone would like me to send pictures of I can do so.